Dist.ribut.us Erasure Codes

Erasure codes will end up being used in many places. Right now I'm using [github.com/klauspost/reedsolomon Reed-Solomon] but Raptor Codes look better. However, they're really confusing.

There is a Go version but it doesn't look like it's in great shape, but it may be enough for me to clean it up. I can use this Python version as a reference.